Features 1、When the door is opened, the door will sound an alarm. It can prevent your child from slipping out. 2、Not only can guarantee the safety of children, but also used for anti‑theft, family and business safety. 3、It can be installed easily, with adhesive at the bottom, just stick the alarm sensor on the door and window to complete the installation. 4、This door alarm is very suitable for elderly people living alone, busy mothers, and hurried office workers to use. 5、Fast automatic switch function, super sensitive magnetic sensor can quickly detect the status of your door and window. Specifications Condition: 100% Brand New Item Type: Door Sensor Alarm Material: ABS Product Size: Approx. 7.5x5.2x3.5cm/3x2.1x1.4in Weight: Approx. 80g/2.8oz Battery: 3 x AAA Batteries (Not Included) Scope of Application: Elderly People Living Alone, Busy Mothers, and Hurried Office Workers Firm Sticker Bearing: Approx 10kg/22lb Function: Chinese and English Bilingual Reminder Package List 1 x Door Sensor Alarm Reminder 1 x Adhesive Tape